piperidines and mequitazine

In order to assess the efficacy of an antihistaminic eye drop containing 0.05% mequitazine in the prevention of allergy induced by a conjunctival provocation test, a double-masked, randomized, intraindividual study compared this eye drop to 0.05% levocabastine and 0.1% dexamethasone eye drops in 24 subjects allergic to grass pollen.. During the first phase of treatment, randomized subjects received one drop of dexamethasone in one eye and one drop of either mequitazine or levocabastine in the fellow eye. During the second phase of treatment, they were given one drop of dexamethasone in the same eye as previously, and one drop of the treatment that had not been given during the first phase (levocabastine or mequitazine) in the fellow eye. Fifteen minutes after each instillation phase, a conjunctival provocation test was performed. Hyperemia, itching, tearing, chemosis and palpebral edema were the five signs or symptoms taken into account to assess the treatment efficacy. Their intensity was evaluated 3, 5 and 10 min after the conjunctival provocation test. The primary efficacy criterion was the global score obtained by measuring hyperemia and itching intensity.. The score was reduced significantly more (p < 0.0001) for the eyes treated with mequitazine or levocabastine than for those treated with dexamethasone at all evaluation times. The difference was also significant for hyperemia (p < 0.001), itching (p < 0.001), and tearing (p < 0.05). The tolerability of the three eyedrops was satisfactory.. Mequitazine and levocabastine were safe and significantly more effective than dexamethasone in preventing the allergic response induced by a conjunctival provocation test when they were instilled 15 min before contact with the allergen.

Topics: Adult; Allergens; Anti-Allergic Agents; Anti-Inflammatory Agents; Conjunctiva; Conjunctivitis, Allergic; Data Interpretation, Statistical; Dexamethasone; Double-Blind Method; Female; Histamine H1 Antagonists; Humans; Male; Middle Aged; Ophthalmic Solutions; Phenothiazines; Piperidines; Time Factors

A double masked randomised trial comparing 0.05% mequitazine eye drops with 0.05% levocabastine and placebo was carried out in otherwise healthy volunteers allergic to house dust mites (Dermatophagoides pteronyssinus).. Double masked, randomised, single centre study, comparing three parallel treatment groups. 60 healthy adults with a confirmed history of allergic conjunctivitis to house dust mites for at least 2 years were included and completed the trial. Conjunctival provocation tests (CPT) were done at screening, at visit 2 (V2) (1 week later), and at visit 3 (V3) (2 weeks after V2). Treatment was instilled in the same eye, 5 minutes after the CPT at V2, and twice daily until V3. CPT were scored 5, 10, 15, and 60 minutes after instillation of the dose of Dermatophagoides pteronyssinus antigen determined at inclusion (V2, curative test) or resulting in positivity (V3, preventive test). In the V2 (curative) test the difference between the active treatments and placebo on the redness+itching scores was not significant. At the V3 (preventive) CPT there was a lower number of reactions at the threshold dose with mequitazine (20%) compared to placebo (60%, p = 0.01) or levocabastine (45%, p = 0.10).. This trial failed to clearly demonstrate curative superiority of topical antihistamines with placebo, when a single dose of treatment was instilled following CPT. However mequitazine 0.05% eye drops were superior to placebo in preventing a reaction to CPT, after 2 weeks of treatment.

Topics: Adolescent; Adult; Chi-Square Distribution; Conjunctivitis, Allergic; Dermatophagoides pteronyssinus; Double-Blind Method; Female; Histamine H1 Antagonists; Humans; Male; Middle Aged; Ophthalmic Solutions; Phenothiazines; Piperidines; Statistics, Nonparametric

The anti-allergic activity of ebastine, a novel antihistamine, was assessed in comparison with several antihistamines. 1) Orally administered ebastine dose-dependently inhibited 7-day homologous passive cutaneous anaphylaxis (PCA), experimental allergic rhinitis and experimental asthma in guinea pigs or rats (ED50-values were 2.17, 0.29 and 0.35 mg/kg, respectively); and its anti-allergic activity was more potent than those of terfenadine and mequitazine. Moreover, its PCA-inhibitory activity was still observed 24 hr after the administration. 2) Orally administered ebastine also inhibited histamine-induced skin reaction in rats (ED50: 1.10 mg/kg). 3) In isolated guinea pig trachea, ebastine had no effect on histamine-induced contraction, but carebastine, a main metabolite of ebastine, inhibited this contraction (IC50: 0.12 microM). 4) Carebastine (30-100 microM) suppressed the histamine release from rat peritoneal mast cells and human basophils. 5) Ebastine at a high oral dose showed slight inhibition of the specific binding of 3H-mepyramine to the histamine H1-receptor in rat brain. This binding-inhibitory activity of ebastine was little more potent than that of terfenadine, but much less potent than those of mequitazine and ketotifen. These results indicated that ebastine has potent and long acting anti-allergic activity with few side effects based on the antihistaminic activity in the central nervous system. Furthermore, it was suggested that these effects of ebastine are due to the action of a main metabolite, carebastine.

Topics: Administration, Oral; Animals; Butyrophenones; Disease Models, Animal; Dose-Response Relationship, Drug; Guinea Pigs; Histamine H1 Antagonists; Histamine Release; Humans; Hypersensitivity; In Vitro Techniques; Male; Phenothiazines; Piperidines; Pyrilamine; Rats; Rats, Wistar; Terfenadine